Obesity is a global health issue. Treatment or prevention of obesity via lifestyle change remains elusive, particularly due to the lack of patient compliance and the subsequent weight regain following the cessation of dietary intervention. The hypothalamus is pivotal in regulating energy homeostasis by matching up energy intake and expenditure. Therefore, identifying novel mechanisms underlying these processes will provide new insights into the treatment of obesity. High-fat feeding has been reported to induce functional and structural impairment of the hypothalamus( Reference Thaler, Yi and Schur 1 – Reference Zhang, Zhang and Zhang 3 ) leading to leptin( Reference Koch, Lowe and Pretz 4 ) as well as ghrelin resistance( Reference Briggs, Enriori and Lemus 5 ). As a consequence regulation of energy homeostasis is disrupted.
Microarray analysis identified a novel gene, SerpinA3N, highly up regulated in hypothalamic neurons of mice in response to consumption of a high-fat diet (HFD) and intraperitoneal (IP) injections of leptin( Reference Williams, Grant and Morris 6 ). We sought to investigate whether SerpinA3N plays a role in energy balance by using a hypothalamic cell line model.
Initial results confirm that SerpinA3N is expressed in the hypothalamic neuronal cell line as assessed by PCR (Fig. 1). Its expression is up regulated by both leptin (P < 0·001) and palmitic acid (P < 0·001) challenge (Fig. 2). Statistical analysis was carried out using one-way ANOVA.
Western blot revealed that alpha-1-antichymotrypsin (the protein encoded by SerpinA3) is secreted into the cell culture medium. Further studies are required to identify its role in hypothalamus as well as its downstream target(s) and post-translational modifications.